The American Academy of Pediatrics recently released an article recommending that pediatricians initiate an evaluation for ADHD for children as young as 4 and up to 18, who present with academic or behavioural impairment and symptoms of inattention, hyperactivity and impulsivity. This expands the previous 6 to 12 age range. Since in the vast majority of cases ADHD is inherited it would be reasonable to assume the child has the condition from birth. We also know that early intervention can be very beneficial, and that ADHD symptoms most often continue into adolescence and adulthood.
The paper recommends that for preschoolers the first line of treatment be evident-based parent and/or educator behaviour therapy, and if these therapies do not improve impairments sufficiently medication be included in the treatment plan. Clinicians would have to weigh the risks of starting medication at an earlier age with the harm of delaying the diagnosis and treatment.